Wednesday 28 October 2015

Symphysanodon andersoni: A second specimen of the Bucktoothed Slopefish from the south coast of Oman.

Slopefish, Symphysanodontidae, are deepwate Perciform Fish known from the Atlantic, Indian and Pacific Oceans. Like many deepwater orgnanisms the biology and diversity of the group is poorly understood, with most species being known from only a very few number of specimens captured in deep sea trawls. To date only twelve species have been described, all of which are placed in a single genus, Symphysanodon, with another undescribed species known from a single specimen recovered from the stomach of a Coelacanth captured in the Comoros Islands. The Bucktoothed Slopefish, Symphysanodon andersoni, is known only from a single specimen caught at a depth of 190-290 m to the southwest of the Socotra Islands in the Guf of Aden in 1974 (three further specimens assigned to this species reported from the Gulf of Kutch, an inlet in the northeastern quadrant of the Arabian Sea on the west coast of India in 2003 have now been re-assigned to another species).

In a paper published in the journal Zootaxa on 28 September 2015, William Anderson of the Grice Marine Biological Laboratory at the College of Charleston, Mikhail Chesalin of the Fisheries Research Center-Salalah of the Ministry of Agriculture and Fisheries Wealth of the Sultanate of Oman, Laith Jawad of Flat Bush, New Zealand and Said Al Shajibi, also of the Fisheries Research Center-Salalah of the Ministry of Agriculture and Fisheries Wealth of the Sultanate of Oman, describe a second specimen of Symphysanodon andersoni from a Fish trap at a depth of about 80 m off Raysut Port on the south cast of Oman.

This specimen is identified as belonging to the same species as the original by the number of tubed scales along the lateral line, which is larger in this species than in other members of the genus, plus the number of gillrakers and depth of the body at the origin of the dorsal fin. It is 204 mm in length, larger than the original specimen (157 mm), and a dark orange-red in colour.

Freshly collected specimen of Symphysanodon andersoni caught in a fish trap off the south coast of Oman. Mikhail Chesalin in Anderson et al. (2015).

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